No parent's agenda is for their child to be kicked around by another kid.
The consequence is that every parent, given a scenario where they feel their kid is being kicked around, will remove their kid from that situation.
That's not a healthy absolute either.
Clearly, I'm not talking about extreme abuse.
But I am talking about more discomfort than I (as the parent) would want for the child in my ideal world.
Parenting is always wanting your child to suffer as little as possible. But a little suffering is good in the long run for the child.
Thus, the fundamental tension in letting parents be the ultimate arbiters of a child's experience.
But yes, I think it's healthy for my children to experience more suffering than I, ceteris paribus, would permit them to experience, if I were omnipotent.